Active Imaging Device Having Field of View and Field of Illumination With Corresponding Rectangular Aspect Ratios

Abstract

Active imaging devices can include a camera and an illuminator that provides light to the scene under observation. Most often, a laser beam combined with projector optics is used to generate a field of illumination while a telescope and a camera are use to acquire the images in its field of view. This specification demonstrates the production of a rectangular field of illumination having a highly uniform intensity distribution matching and aligned with a rectangular field of view of the camera.

What is claimed is: 
     
         1 . An active imaging device having: a fiber illuminator having a rectangular illumination area; a projector lens group having a focal plane coupleable to the rectangular illumination area to project a corresponding rectangular field of illumination on a scene located in the far field of the projector lens group, a camera having a camera sensor and a rectangular field of view alignable with the rectangular field of illumination, the field of view and the field of illumination having matching rectangular aspect ratios. 
     
     
         2 . The active imaging device of  claim 1  wherein the fiber illuminator has an optical fiber having an input end coupled to a light source and an output end. 
     
     
         3 . The active imaging device of  claim 2  wherein the output end has a rectangular core delimiting the rectangular illumination area at the output end thereof. 
     
     
         4 . The active imaging device of  claim 3  wherein the optical fiber is an integral rectangular core optical fiber. 
     
     
         5 . The active imaging device of  claim 3  wherein the optical fiber has an input section having a circular core and an output section having the rectangular core. 
     
     
         6 . The active imaging device of  claim 5  wherein the output section has a rectangular light pipe. 
     
     
         7 . The active imaging device of  claim 5  further comprising a fusion connection between the output section and the input section. 
     
     
         8 . The active imaging device of  claim 2  wherein the output end is coupled to a mask having a rectangular aperture delimiting the rectangular illumination area. 
     
     
         9 . The active imaging device of  claim 2  wherein the optical fiber is multi mode and delivers uniform intensity across the rectangular illumination area. 
     
     
         10 . The active imaging device of  claim 2  wherein the light source is one of a laser source and a LED source. 
     
     
         11 . The active imaging device of  claim 1  wherein camera sensor is coupled to a telescope lens group. 
     
     
         12 . The active imaging device of  claim 1  wherein the camera sensor is coupled to the projector lens group. 
     
     
         13 . The active imaging device of  claim 1  wherein the fiber illuminator is operable in pulse mode and the camera sensor is range gated. 
     
     
         14 . The active imaging device of  claim 1  wherein the fiber illuminator is operable in continuous mode. 
     
     
         15 . The active imaging device of  claim 1  wherein the camera, fiber illuminator, and projector lens group are mounted to a common frame of the active imaging device. 
     
     
         16 . An active imaging device having: a frame; a camera mounted to the frame, having a camera sensor, and a field of view having a camera aspect ratio; a fiber illuminator mounted to the frame and having a rectangular cross-section light output path corresponding to the camera aspect ratio; and a projector lens group mounted to the frame, the projector lens group being optically coupleable to the light output path of the fiber illuminator for projection into a field of illumination aligned with the field of view of the camera. 
     
     
         17 . The active imaging device of  claim 16  wherein the fiber illuminator has an optical fiber having an input end coupled to a light source and an output end and having a rectangular core delimiting the rectangular illumination area at the output end. 
     
     
         18 . The active imaging device of  claim 16  wherein the fiber illuminator has an optical fiber having an input end coupled to a light source and an output end coupled to a mask having a rectangular aperture delimiting the rectangular illumination area. 
     
     
         19 . The active imaging device of  claim 16  wherein the optical fiber is multi mode and delivers uniform intensity across the rectangular illumination area. 
     
     
         20 . The active imaging device of  claim 16  wherein camera sensor is coupled to a telescope lens group determining the field of view.